1. Field of the Invention
The present invention relates generally to a signal detector and a signal detection method, and more particularly, to a signal detector and a signal detection method adapted for detecting a voltage signal. The signal detector of the present invention is configured in a manner of integrated circuit (IC), and is capable of detecting a voltage level, and/or a frequency, and/or a zero point, and/or a phase of a signal inputted thereto, and is further adapted for determining whether the detected factor is abnormal, and is further capable of outputting interrupt signal for subsequent processing.
2. The Prior Arts
Typically, a conventional voltage detection circuit includes an analog-to-digital converter (ADC), a timer, and a micro-controller unit (MCU) firmware. When such a conventional voltage detection circuit is used in detecting whether a voltage signal, e.g., a mains voltage signal, is normal, the ADC in the voltage detection circuit architecture, repetitively executes sampling/ converting operations to the voltage signal (e.g., attenuated and full-wave rectified mains voltage signal) for monitoring the level of the voltage signal. At least 16 times of sampling/converting operations are executed to each half-cycle of the voltage signal. A positive edge and a negative edge of a square wave signal (e.g., a square wave signal having a mains frequency) are taken serving as an initial signal of each half-cycle. For example, the time width of each half-cycle of the voltage signal is 8.33 ms (60 Hz mains power), or 10 ms (50 Hz mains power). Then, if the track of the voltage signal successively exceeds an upper threshold and a lower threshold, the voltage is determined as abnormal. Then, the timer is used for converting the square wave signal, for learning the frequency of the voltage signal (e.g., the attenuated and full-wave rectified mains voltage signal). Finally, if the frequency of the voltage signal successively exceeds a predetermined upper threshold and a predetermined lower threshold (e.g., 50 Hz ±3 Hz), the frequency is determined as abnormal.
However, in such a conventional voltage detection circuit architecture, the ADC is not an IC, and therefore the conventional voltage detection circuit has the disadvantage of a lower stability and is apt to be affected by environmental factors (e.g., operation temperature). Further, being of a non-integrated circuit, the ADC cannot be integrated with other ICs, and therefore is not adapted for system integration. As such the application of such a voltage detection circuit architecture is restricted.
In this concern, it is desired to develop an IC type voltage detection circuit, which is capable of detecting a factor of a voltage signal, such as a voltage level (e.g., 110V or 220V mains power) and/or a frequency (e.g., 60 Hz or 50 Hz mains power), and/or a zero point, and/or a phase, and determining whether the factor is abnormal, and is further capable of outputting interrupt signal for subsequent processing.